Ok, I did some testing with the spec and although I lack a lot of good gear (I have anathema/benediction though and lots of bis) I did pretty well in a ZG run yesterday.
http://db.vanillagaming.org/?talent#bxRMsZZAGgzctotThis is what I am using right now.
The single target dps is awesome (I was constantly in the first place or second place in trash), I didn't draw any threat whatsoever and I rarely went OOM (well in long fights I am still using 2 pieces of t1: belt + shoulders and laugh all you want, BUT I didn't run OOM and dps is more than decent, besides what's the use of having a few more spell damage if you run OOM in no time?). Also spirit tap is pretty usefull in fights with adds. If you can time some MBs and you got spirit tap procs it's awesome. Of course in between in bosses I used mana potion and demonic rune/dark rune or night dragon's breath.
I also noticed that with that amount of mp5 I can spam mind flay rank 1 forever so I can keep the debuff up for locks.
This was though a ZG run and I am all new to shadow priest because I was healer till now. I will try out ony and MC the couple next days and I will tell you what happens.
Full buffed I have almost 4k hp and more than 7k mana. Overall spell damage is low though and anathema is enchanted with + healing
Any thoughts? Feedback of experienced shadow priests is appreciated